论文标题
可重新配置的智能表面辅助秘密密钥一代中的联合预编码和相移设计
Joint Precoding and Phase Shift Design in Reconfigurable Intelligent Surfaces-Assisted Secret Key Generation
论文作者
论文摘要
密钥生成是一种有前途的技术，可以在资源受限的合法用户之间建立对称键。但是，在频道随机性受到限制的恶劣环境中，密钥生成遭受低秘密关键率（SKR）。为了解决该问题，引入了可重构智能表面（RISS），以通过控制大量反射元素来重塑渠道，这可以提供更多的频道多样性。在本文中，我们设计了一个通道探测协议，以通过反射元素从级联的通道（即通道）完全提取随机性。我们得出了SKR的分析表达式，并根据Karush-Kuhn-Tucker（KKT）条件设计了一种填充水算法，以找到上限。为了找到最佳的预编码和相移矩阵，我们提出了一种基于Grassmann歧管优化方法的算法。根据SKR，位分歧率（BDR）和随机性评估该系统。模拟结果表明，与现有协议相比，我们的协议显着改善了SKR。
Key generation is a promising technique to establish symmetric keys between resource-constrained legitimate users. However, key generation suffers from low secret key rate (SKR) in harsh environments where channel randomness is limited. To address the problem, reconfigurable intelligent surfaces (RISs) are introduced to reshape the channels by controlling massive reflecting elements, which can provide more channel diversity. In this paper, we design a channel probing protocol to fully extract the randomness from the cascaded channel, i.e., the channel through reflecting elements. We derive the analytical expressions of SKR and design a water-filling algorithm based on the Karush-Kuhn-Tucker (KKT) conditions to find the upper bound. To find the optimal precoding and phase shift matrices, we propose an algorithm based on the Grassmann manifold optimization methods. The system is evaluated in terms of SKR, bit disagreement rate (BDR) and randomness. Simulation results show that our protocols significantly improve the SKR as compared to existing protocol.
